Continuation is proposed of a program for study of mammalian carbohydrases, with the goal of contributing to the detailed understanding of glycosaminoglycan catabolism. Among the immediate objectives are the more efficient purification and characterization of alpha-acetylglucosaminidase and alpha-L-iduronidase, in connection with which chemical syntheses of appropriate substrates (aryl glycosides) are under study. We have also undertaken preparation of appropriate oligosaccaride substrates, by chemical degradation of heparin and modification of fragments, to study the mode of catabolism of N-sulfo- alpha-glucosaminyl linkages in heparin sulfate.